Milk Production In Dairy Cows Research Articles

Disturbances of Ruminal Microbiota and Liver Inflammation, Mediated by LPS and Histamine, in Dairy Cows Fed a High-Concentrate Diet.

The ecosystem of ruminal microbiota profoundly affects the health and milk production of dairy cows. High-concentrate diets are widely used in dairy farms and evoke a series of metabolic disorders. Several studies have reported the effects of high-concentrate diets on the ruminal microbiome, while the effect of changes in ruminal microbial flora, induced by high-concentrate diet feeding, on the liver of dairy cows has not been studied before. In this study, 12 mid-lactating Holstein Friesian cows (weight of 455 ± 28 kg; parities of 2.5 ± 0.5; starting milk yield of 31.59 ± 3.2 kg/d; DMI of 21.7 ± 1.1 kg/d; and a DIM at the start of the experiment of 135 ± 28 d) were fitted with ruminal fistulas, as well as with portal and hepatic vein catheters. All cows were randomly divided into 2 groups; then, they fed with low-concentrate diets (LC, concentrate: forage = 40:60) and high-concentrate diets (HC, concentrate: forage = 60:40) for 18 weeks. The forage sources were corn silage and alfalfa hay. After the cows of two groups were euthanized over two consecutive days, ruminal microbiota; the concentration of LPS in the rumen content; cecum content; the levels of blood and histamine in rumen fluid, blood, and the liver; the histopathological status of the rumen and cecum; and the inflammatory response of the liver were assessed in dairy cows under conditions of subacute ruminal acidosis (SARA). These conditions were caused by high-concentrate diet feeding. All data were analyzed using the independent t-test in SPSS. The results showed that high-concentrate diet feeding increased the concentration of LPS and histamine in the rumen and plasma of veins (p < 0.05). The abundance of Bacteroidetes at the phylum level, and of both Bacteroidetes and Saccharibacteria at the genus level, was decreased, while the abundance of Firmicutes at the phylum level and Oscillibacter at the genus level was increased by high-concentrate diet feeding. The decreased pH values of ruminal contents (LC = 6.02, HC = 5.90, p < 0.05) and the increased level of LPS in the rumen (LC = 4.921 × 105, HC = 7.855 × 105 EU/mL, p < 0.05) and cecum (LC = 11.960 × 105, HC = 13.115 × 105 EU/mL, p < 0.01) induced the histopathological destruction of the rumen and cecum, combined with the increased mRNA expression of IL-1β (p < 0.05). The histamine receptor H1R and the NF-κB signaling pathway were activated in the liver samples taken from the HC group. In conclusion, the elevated concentrations of LPS and histamine in the gut may be related to changes in the ruminal microbiota. LPS and histamine induced the inflammatory response in the ruminal epithelium, cecum epithelium, and liver. However, the cause-effect mechanism needs to be proved in future research. Our study offers a novel therapeutic strategy by manipulating ruminal microbiota and metabolism to decrease LPS and histamine release and to improve the health of dairy cows.

Milk production and nitrogen excretion of grazed dairy cows in response to plantain (Plantago lanceolata) content and lactation season.

The study aimed to quantify milk production and urinary nitrogen (UN) excretion of dairy cows grazing pastures containing varying contents of plantain (Plantago lanceolata) in different seasons, under a typical farm practice. Four pasture treatments: perennial ryegrass (Lolium perenne) - white clover (Trifolium repens) (RGWC), RGWC + low plantain rate, RGWC + medium plantain rate, and RGWC + high plantain rate, were established in four adaptation areas (1 ha each) and 20 experimental plots (800 m2 each), and rotationally grazed by dairy cows over 14 grazing events during two lactation years. In each grazing (8-9 days), 60 or 80 Jersey-Friesian lactation cows were assigned to their pasture treatments, adapted to their pastures over the first six days, then each group of 15 or 20 cows were randomly allocated for grazing in five treatment plots over a two or three-day measurement period. Milk, urine, and faecal samples were collected from individual cows during the measurement period. The pasture treatments did not affect milk production, the yield and composition of milk solids, protein, fat, and lactose. However, cows grazing pastures containing between 17-28% dietary plantain reduced UN concentration by 15-27%, decreased UN excretion by 4-9%, and increased urine volume by 22-40%, compared to grazing the RGWC pasture. The change in UN concentration, and urine volume were associated with plantain proportion in the diet and were greater during late summer and autumn than during early summer. Incorporating 17%-28% dietary plantain with RGWC pastures can reduce the risk of nitrogen losses from pastoral systems, while maintaining the milk production of dairy cows.

Association of Mycobacterium avium paratuberculosis serostatus with age at first calving, calving interval, and milk production in dairy cows

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of bovine paratuberculosis, also known as Johne's disease. This infection is responsible for negative effects, ranging from reduction of milk production to reproductive compromise and increased susceptibility to other diseases such as mastitis. Contradictory information on the association between this infection and reproductive performance has been reported in dairy cows. The aim of this work was to investigate associations between individual cow MAP seropositivity and lifetime reproduction and production performance. The MAP serum ELISA (IDEXX MAP Ac) results from all the 13,071 adult cows present on 191 farms and corresponding birth- and calving-date records obtained from the National Association for Genetic Improvement of Dairy Cattle were used. Cows and farms were classified as positive or negative, based on ELISA results. Outcomes assessed were age at first calving (AFC), intercalving intervals (ICI) from first to fourth interval, and average milk production per day of productive cycle (Milk-305/ICI, a ratio between 305-d corrected milk production and the number of days of the respective calving interval). Multilevel mixed models were used to investigate the association of cow MAP status with AFC, ICI, and Milk-305/ICI. Three levels were considered in the models: "measurement occasion," the first level, was nested within cows and cows were nested within farms. The "measurement occasion" is the time point to which all the observed measures (between 2 successive parturitions, such as milk production and somatic cell count) were referred. Our results indicate that MAP-positive cows have a significantly lower 14-d mean AFC than MAP-negative cows. The overall average ICI in our study was 432.5 d (standard deviation: 94.6). The average ICI, from first to fourth, was not significantly affected by MAP seropositivity. No significant effect of MAP positivity was found on the overall ICI. In relation to Milk-305/ICI, MAP-positive cows did not produce significantly less milk than negative cows across their productive lifetime. We observed higher but nonsignificant Milk-305/ICI (kg/d) in MAP-positive cows. In our study, the proportion of MAP-positive cows within lactations remained similar across all lactations, suggesting that seropositivity did not increased drop-off rate.

Productivity of cows of the red steppe breed, considering the physique

As a result of a comparative assessment of the qualitative indicators of milk productivity of dairy cows of the red steppe breed of the III lactation, two controlled groups of animals were selected for the study according to two body types. It was found that broad-bodied cows have higher milk yields by 5.91% compared to narrow-bodied animals. Broad-bodied cows also produce more milk fat and protein during the standard lactation period, by an average of 21.36% and 20.5%.

The milk production of recovered dairy cows from foot-and-mouth disease in the Medowo Village, Kandangan Subdistrict, Kediri

The outbreak of Foot-and-Mouth Disease (FMD) has caused a crisis for Indonesian farmers, particularly dairy cattle in Medowo village. The FMD outbreak affected the whole dairy cow population in Medowo, resulting in major losses defined by high mortality rates and a halt in milk production during the cows' FMD infection. Dairy cows, which are essential for maintaining milk production and providing an economic foundation for Medowo's farmers, led our team to execute community service from January to August 2023. Socialization and data collection on farmers and their cows were followed by laboratory testing for mastitis identification and treatment. The outreach events focused on mastitis care for cows, promoting talks to solve farmers' issues, particularly in livestock health. Farmers were instructed on how to report subclinical mastitis instances to appropriate authorities, were trained on how to prepare fermented feed/silage with probiotics to improve feed quality, and were monitored for overall evaluation. The milk production data collected showed that morning yield produce higher quantity than afternoon yield. The lowest milk production occurs in September, while the highest is observed in November. Overall, data from dairy cow milk production in Medowo Village after FMD outbreak show a satisfactory result, illustrating the success of community service programs. Future initiatives should include collecting data on a regular basis to allow for ongoing evaluation and continued improvement in milk production.

Effect of chop length of grass silage harvested at two maturity stages, and of concentrate protein level, on feed intake and milk production in dairy cows

AbstractThis study in dairy cow feeding explored the effects of growth stage and chop length for grass‐clover silage, and of concentrate protein level, including the interactions of these three factors. The experiment was conducted with 48 Norwegian Red cows according to a cyclic change‐over design with four 4‐week experimental periods and eight dietary treatments in a 2 × 2 × 2 factorial arrangement. Round bale silage from a mixed sward of timothy, meadow fescue, and red clover was harvested at two growth stages (H1, H2) and offered to dairy cows either unchopped with median particle length of 152 mm or chopped to 19 mm median particle length before feeding. A low protein (LP) concentrate containing 7% lignosulphonate treated soybean meal (SBM) and a high protein (HP) concentrate containing 12% solvent extracted SBM were compared. Silage was offered ad libitum and supplemented with 8 kg concentrate per day. Silage dry matter intake was 2.0 kg higher for H1 than H2 silage, which supported a higher yield of milk, energy‐corrected milk and the milk constituents, fat, protein, and lactose. All these measures of milk production, as well as feed energy efficiency and N use efficiency, increased when silage was fed chopped rather than unchopped. Lignosulphonate treated SBM spared N in the diet without milk yield reductions. For efficient milk production with high energy and N utilisation, we recommend chopping to 20 mm for timothy, meadow fescue, and clover silages harvested in late stem elongation or in reproductive growth stages.

Effects of grass silage, preserved using formic acid or lactic acid bacteria, on milk production of dairy cows, supplemented with concentrates high or low in metabolizable protein

A continuous production experiment was conducted in Norway with 48 Norwegian Red dairy cows in early- to mid-lactation, to investigate the effect of grass silage with lactic acid bacteria (LAB) or formic acid (FA) additives, on milk yield (MY) and milk protein yield (MPY). Grass wilted to 250 g dry matter (DM)/kg was inoculated with homofermentative LAB to obtain LAB silage, whilst FA silage was produced adding a FA-based additive. The two silages were fed ad libitum and supplemented with an average 10.3 kg of either high (H) or low (L) metabolizable protein (MP) concentrates, in a 2 ✗ 2 factorial arrangement of treatments. The treatments were LAB silage and L concentrate, LAB silage and H concentrate, FA silage and L concentrate and FA silage and H concentrate. The use of FA resulted in lower levels of residual water-soluble carbohydrates (WSC), and higher levels of ammonia nitrogen (NH3N), compared to LAB. In situ results for FA silage showed lower rumen degradability of crude protein (CP), while gas in vitro results showed lower utilizable CP (uCP), compared to LAB silage (782 vs. 750 g/kg DM and 128 vs. 119 g/kg DM, respectively). The purine over creatinine (PDC) index did not indicate any effects on the microbial protein synthesis (MPS) from any of the treatments. The higher daily intake of FA silage (12.5 vs.13.7 kg DM for LAB and FA, respectively, P < 0.001), did not result in significant differences in daily MY (31.0 vs. 30.2 kg, P = 0.208), nor MPY (1.08 vs.1.07 kg/day, P = 0.878) for LAB and FA, respectively. Feeding H concentrate gave higher MPY (P = 0.036), higher urea in milk (P < 0.001), plasma (P < 0.001) and urine (P = 0.008) and tended to give higher MY (P = 0.063) for both silages. For amino acids (AA) in plasma, alanine was higher for FA silage than for LAB silage (P = 0.030), while histidine (P = 0.001), leucine (P = 0.015) and glutamine (P = 0.007) were higher for both silages when cows were fed H concentrate. In conclusion, the FA and LAB additives did not affect MY or MPY any differently. Feeding H concentrate resulted in higher MPY for both silages, but reduced nitrogen (N) efficiency.

The The Relationship Between Lactation Period With Colostrum Age And Colostrum Fat Content Of FH (Friesian Holstein) At Kpsp Setia Kawan, Pasuruan

Colostrum is the milk secreted by the mother cow on the first day until the fourth day of milking after giving birth sothat it becomes the main food for the calf. The decrease in the milk production of dairy cows is in line with the increasein the lactation period. The effect of lactation period and colostrum age on colostrum fat content needs to beinvestigated because many small farmers do not understand the importance of colostrum for calves, especiallycolostrum fat content. The research location is in the Cattle Farming Cooperative. Dairy (KPSP) Faithful Friend. Dairycows used were 23 FH cows with a sample of 115 samples with 3 lactation periods (1,2,3) and 1,2,3,4,5 milking days.The method used is the case study method and sampling with purposive sampling. The variables used were lactationperiod, age and colostrum fat. data were analyzed using simple linear regression and correlation then analyzed usingdescriptive results. The relationship between lactation period and colostrum fat content is Y 7.43 + 0.03X, which meansthat every increase of 1 lactation period will result in an increase in colostrum fat content of 0.03%. With a correlationcoefficient (r) of 0.013 and a determination coefficient (R2) of 0.01%. while the average age of colostrum with thehighest colostrum fat content on the first day was 8.79 while the smallest fat content on the fifth day was 5.85. Basedon the results of the study it can be concluded that lactation period is not associated with the highest colostrum fatcontent on day 1 and the lowest on day 5.Keywords: Colostrum, lactation period, colostrum age, fat

The effect of teff (Eragrostis tef) hay inclusion on feed intake, digestibility, and milk production in dairy cows

Teff (Eragrostis tef) is a drought-tolerant, multi-harvest, high-quality summer forage crop. We conducted a study aiming at assessing the effect of replacing wheat hay with teff hay in diets on the feed intake, digestibility, and lactational performance of dairy cows. Thirty-four multiparous (≥3rd parity) Israeli Holstein Friesian dairy cows averaging (± SD) 182 days in milk ± 8 days in milk, 45 kg/d ± 4.8 kg/d of milk yield, and a body weight of 647.1 kg ± 51 kg at the beginning of the study were recruited to a 6-week feeding trial. Cows were randomly divided into two balanced groups based on parity, days in milk, and milk yield. Cows were subjected to two low-roughage dietary treatments (~30% roughage): a control wheat hay-based diet and a teff hay-based diet. Production performances, dry matter intake, and nutrient digestibility were measured. Milk samples were analyzed for their composition and fatty acids profile. Blood samples were used to measure metabolite concentrations. The statistical model included fixed effects of dietary treatments, time, and random effects of cows nested in treatment. Production data and feed intake were analyzed as repeated measures using a covariance structure. Dietary treatments did not affect dry matter intake (26 kg/d). However, the teff-fed cows demonstrated higher crude protein digestibility than control cows (61.9% vs. 59.2%). Dietary teff inclusion increased milk yield by 1.5 kg/d. Polyunsaturated fatty acids and omega-3 fatty acids profiles in milk were greater in the teff cows than in the control cows (4.77 g/100 g vs. 4.36 g/100 g and 3.71 g/100 g vs. 3.43 g/100 g, respectively). Non-esterified fatty acids, beta-hydroxybutyrate, and blood urea nitrogen concentrations in circulation were higher in the control group than in the teff group. The acetic-to-propionic-acid ratio in the rumen fluid was higher in control cows than in teff cows (2.90 vs. 2.43). However, the ruminal ammonia-N concentration was higher in the teff cows than in the control cows (18.5 mg/dL vs. 15.8 mg/dL). In conclusion, teff hay inclusion in the rations of high-producing dairy cows increased milk yield, which could be attributed to improved crude protein digestibility and energy partition to production.

Sirtuin 3 mitigates oxidative-stress-induced apoptosis in bovine mammary epithelial cells

Ketosis is often accompanied by a reduction in milk production in dairy cows, but the molecular mechanism has not been fully elucidated. Ketotic cows possess systemic oxidative stress (OS), which may implicate apoptosis in mammary glands. Sirtuin 3 (SIRT3) is a vital regulator of cellular redox homeostasis and is under the control of AMP-activated protein kinase (AMPK) signaling in nonruminants. Thus, we aimed to investigate (1) the AMPK-SIRT3 and apoptosis status of mammary glands from ketotic cows, (2) the effect of SIRT3 on OS-induced apoptosis in bovine mammary epithelial cells (BMEC), and (3) the role of AMPK signaling on SIRT3-mediated effects on apoptosis. Mammary gland samples were reused from a previous study, which contained healthy and ketotic cows (both n = 15). BMEC were incubated with 0, 0.3, 0.6, or 0.9 mM H2O2 for 6 h with/without a 30 min incubation of an antioxidant MitoQ (1 μM). Then BMEC were incubated with SIRT3 overexpression adenovirus (Ad-SIRT3) for 6 h followed by a 6 h incubation with 0.6 mM H2O2. Finally, BMEC were treated with the AMPK inhibitor Compound C (Cd C,10 μM) for 30 min before the H2O2 challenge, or cells were initially treated with the AMPK agonist MK8722 (10 μM) for 30 min followed by a 30-h culture with/without si-SIRT3 and eventually the H2O2 exposure. Ketotic cows displayed higher levels of Bax, Caspase-3 and Bax/Bcl-2 but lower levels of Bcl-2 in mammary glands. H2O2 incubation displayed similar results, exhibiting a dose-dependent manner between the H2O2 concentration and the apoptosis degree. Mito Q pretreatment reduced cellular reactive oxygen species and rescued cells from apoptosis. Ketotic cows had a lower mammary protein abundance of SIRT3. Similarly, H2O2 incubation downregulated both mRNA and protein levels of SIRT3 in a dose- and time-dependent manner. Ad-SIRT3 infection lowered levels of cellular reactive oxygen species, Bax, Caspase-3 and Bax/Bcl-2 but increased levels of Bcl-2. TUNEL assays confirmed that Ad-SIRT3 infection mitigated H2O2-induced apoptosis. Both ketotic cows and H2O2-induced BMEC had lower levels of p-AMPK and p-AMPK/AMPK. Additionally, Cd C pretreatment decreased SIRT3 and Bcl-2 expression but increased levels of Bax and Caspase-3. Contrary to the inhibitor, MK8722 had opposite effects and reduced the percentage of apoptotic cells. However, these effects of MK8722 were reversed upon SIRT3 silencing. In conclusion, in vivo data confirmed that ketosis is associated with greater apoptosis and restricted AMPK-SIRT3 signaling in mammary glands; in vitro data indicated that SIRT3 mitigates OS-induced apoptosis via AMPK signaling. As such, there may be potential benefits for targeting the AMPK-SIRT3 axis to help counteract the negative effects of mammary glands during ketosis.

Effects of dietary fat, nitrate, and 3-nitrooxypropanol and their combinations on methane emission, feed intake, and milk production in dairy cows

The objective of the present study was to investigate the effect of individual and combined use of dietary fat, nitrate, and 3-nitrooxypropanol (3-NOP) on dairy cows' enteric methane (CH4) emission and production performance. Twenty-four primiparous and 24 multiparous Danish Holstein cows (111 ± 44.6 d in milk; mean ± standard deviation) were included in an incomplete 8 × 8 Latin square design with six 21-d periods. Dietary treatments were organized in a 2 × 2 × 2 factorial arrangement aiming for 2 levels of FAT (30 or 63 g of crude fat/kg of dry matter [DM]; LF or HF, respectively), 2 levels of NITRATE (0 or 10 g of nitrate/kg of DM; UREA or NIT, respectively), and 2 levels of 3-NOP (0 or 80 mg/kg DM; BLANK or NOP, respectively). Treatments were included in ad libitum-fed partial mixed rations in bins that automatically measured feed intake and eating behavior. Additional concentrate was offered as bait in GreenFeed units used for measurement of gas emission. For total DM intake (DMI), a FAT × NITRATE interaction showed that DMI, across parities and levels of 3-NOP, was unaffected by separate fat supplementation, but reduced by nitrate with 4.6% and synergistically decreased (significant 2-way interaction) with 13.0% when fat and nitrate were combined. Additionally, 3-NOP decreased DMI by 13.4% and the combination of 3-NOP with fat and nitrate decreased DMI in an additive way (no significant 3-way interaction). The decreasing effects on DMI were more pronounced in multiparous cows than in primiparous cows. For treatments with largest reductions in DMI, eating behavior was altered toward more frequent, but smaller meals, a slower eating rate and increased attempts to visit unassigned feed bins. Energy-corrected milk (ECM) yield increased by 6.3% with fat supplementation, whereas ECM yield did not differ among diets including nitrate (FAT × NITRATE interaction). Cows supplemented with 3-NOP had 9.0% lower ECM yield than cows fed no 3-NOP. Based on three 2-way interactions including FAT, NITRATE, and 3-NOP, the combined use of the additives resulted in antagonistic effects on CH4 reduction. A 6% to 7% reduction in CH4 yield (CH4/kg of DMI) could be ascribed to the effect of fat, a 12% to 13% reduction could be ascribed to the effect of nitrate and an 18% to 23% reduction could be ascribed to the effect of 3-NOP. Hence, no combinations of additives resulted in CH4 yield-reductions that were greater than what was obtained by separate supplementation of the most potent additive within the combination. The CH4 yield reduction potential of additives was similar between parities. Increased apparent total-tract digestibility of organic matter (OM) in cows fed combinations including nitrate or 3-NOP was a result of a NITRATE × 3-NOP interaction. Apparent total-tract digestibility of OM was also increased by fat supplementation. These increases reflected observed decreases in DMI. In conclusion, combined use of fat, nitrate, and 3-NOP in all combinations did not result in CH4 reductions that were greater than separate supplementation of the most potent additive within the combination (3-NOP > nitrate > fat). Additionally, separate supplementation of some additives and combined use of all additives reduced DMI.

Tea polyphenols protect bovine intestinal epithelial cells from the adverse effects of heat-stress in vitro

Heat-stress (HS) leads to impaired gut health, adversely affecting milk production of dairy cows. In the present study, we investigated the protective effects of tea polyphenols (TP) against HS-induced damage in bovine intestinal epithelial cells (BIECs) and explored the underlying mechanisms. Primary BIECs were isolated from bovine duodenum, cultured and treated as follows: (1) control cells incubated in complete medium at 37 °C for 12 h, (2) TP group incubated in medium containing 100 μg/mL TP at 37 °C for 12 h, (3) HS group incubated in medium at 37 °C for 6 h followed by 6 h at 42 °C, and (4) HS + TP group incubated with 100 μg/mL TP for 6 h at 37 °C and 6 h at 42 °C. TP improved cell viability and antioxidant capacity, and decreased apoptosis and LDH activity. TP led to upregulation of Nrf2 and its target antioxidant genes HO-1, NQO1 and SOD1 expression. TP significantly decreased the expression of proinflammatory cytokine genes (NF-κB, IL-6 and TNF-α), and increased expression of the anti-inflammatory cytokine gene, IL-10. The above results suggested that TP protected BIECs from HS-induced adverse effects by alleviating oxidative stress and inflammatory responses, indicating that TP can alleviate HS-induced intestinal damage in dairy cows.

Optimizing hormonal and amino acid combinations for enhanced cell proliferation and cell cycle progression in bovine mammary epithelial cells.

The number of bovine mammary epithelial cells (BMECs) is closely associated with the quantity of milk production in dairy cows; however, the optimal levels and the combined effects of hormones and essential amino acids (EAAs) on cell proliferation are not completely understood. Thus, the purpose of this study was to determine the optimal combination of individual hormones and EAAs for cell proliferation and related signaling pathways in BMECs. Immortalized BMECs (MAC-T) were treated with six hormones (insulin, cortisol, progesterone, estrone, 17β-estradiol, and epidermal growth factor) and ten EAAs (arginine, histidine, leucine, isoleucine, threonine, tryptophan, lysine, methionine, phenylalanine, and valine) for 24 h. Cells were cultured in a medium containing 10% fetal bovine serum (FBS) as FBS supplemented at a concentration of 10% to 50% showed a comparable increase in cell proliferation rate. The optimized combination of four hormones (insulin, cortisol, progesterone, and 17β-estradiol) and 20% of a mixture of ten EAAs led to the highest cell proliferation rate, which led to a significant increase in cell cycle progression at the S and G2/M phases, in the protein levels of proliferating cell nuclear antigen and cyclin B1, cell nucleus staining, and in cell numbers. The optimal combination of hormones and EAAs increased BMEC proliferation by enhancing cell cycle progression in the S and G/2M phases. Our findings indicate that optimizing hormone and amino acid levels has the potential to enhance milk production, both in cell culture settings by promoting increased cell numbers, and in dairy cows by regulating feed intake.

Maternal metabolic status and in-vitro culture conditions during embryonic genome activation deregulate the expression of energy-related genes in the bovine 16-cells embryo.

The molecular consequences of the metabolic stress caused by milk production of dairy cows in the early embryo are largely unknown. The objective was to determine the impact of dam metabolic status or in vitro culture during embryonic genome activation (EGA) on the transcriptomic profiles of bovine 16-cell stage embryos. Two days after synchronized oestrus, in vitro produced 2- to 4-cell stage embryos were endoscopically transferred in pools of 50 into the oviduct ipsilateral to the corpus luteum of lactating (LACT, n = 3) or nonlactating (i.e. dried off immediately at calving; DRY, n = 3) dairy cows. On Day 4, the oviducts were flushed to recover the embryos. Pools of five Day-2 embryos (n = 5) and Day-4 16-cell stage embryos obtained in vitro (n = 3) or from LACT or DRY cows were subjected to RNAseq. Temporally differentially expressed genes (DEG; FDR<0.05) between Day-2 and Day-4 embryos were determined considering the differences between the three conditions under which EGA occurred. Also, DEG between Day-4 embryos derived from the three conditions were identified. Functional analysis of the temporal DEG demonstrated that genes involved in ribosome, translation and oxidative phosphorylation in the mitochondria were strongly more expressed in Day-4 than Day-2 embryos. Comparison of Day-4 embryos that underwent EGA in vitro, or in LACT or DRY cows, identified DEG enriching for mitochondrial respiration and protein translation, including the mTOR pathway. In conclusion, exposure of the embryo to an unfavourable maternal metabolic status during EGA influences its transcriptome and potentially the competence for pregnancy establishment.

High yielding cows metabolism peculiarities under climate change conditions with the use of feed additive with protein protected from rumen degradation

The research relevance is determined by the problem of thermal load on the body of dairy cows by increasing the content of protein protected from breakdown in the rumen. The research aims to determine the metabolism and level of delivery of various forms of protein and energy to the body of highly productive cows in the diets of cows in the second half of lactation under conditions of climate change. Research methods include zootechnical (assessment of feed intake, rationing, selection of groups, organisation of the experiment, determination of milk production), biochemical (determination of the content of basic nutrients in feed, milk quality indicators), statistical, and mathematical. The compensation of protein in the diet of high-yielding cows under climate change conditions was carried out using the protein feed additive TEP-mix with protein protected from rumen breakdown. It has been proven that its inclusion in the cow’s diet can increase average daily milk production by 9.1% in the cold season (0-10°C) and by 28.0% in the summer (21-36.4°C). In addition, the fat and protein content in milk increased in cows receiving the high-protein feed additive TEP mix. It was found that the increase in protein nutrition of cows from 23.18% to 33.53% with the use of the feed additive TEP-mix with protein protected from scar breakdown ensures a reduction in the impact of climate change on the metabolism of dairy cows. Thus, it has been proved that the use of specific protein feed sources that regulate the level of non-cutting protein in the diet can be considered a factor in combating heat stress and increasing milk production of dairy cows throughout the physiological cycle of lactation, including in extreme conditions of high temperatures

The autumn low milk yield syndrome in Brown Swiss cows in continental climates: hypotheses and facts.

Extensive research has been conducted globally on the impact of heat stress (HS) on animal health and milk production in dairy cows. In this article, we examine the possible reasons for the decrease in milk production in Brown Swiss (BS) cows during the autumn season, known as the autumn low milk yield syndrome (ALMYS). This condition has been extensively studied in high-yielding Holstein Friesian (HF) cattle and has also been observed in BS cows with a daily milk yield of around 30kg. Our hypothesis is that the drop in milk yield and the increased prevalence of mastitis in autumn, as found in our recent studies, may be a long-term consequence of summer HS. We re-evaluate our previous findings in light of the possible manifestation of an HS-related form of ALMYS in BS cows. As milk yield, mastitis spread, and reproductive function of cows are interrelated and have seasonal dependence, we examine the consistency of our hypothesis with existing data. The significant drop in milk yield in BS cows in autumn (by 2.0-3.2kg), as well as the threshold of milk yield decrease (temperature-humidity index of 70.7), may point in favour of the manifestation of ALMYS in BS cows, similar to HF cows. Only the percentage effect of seasonal factor (59.4%; p < 0.05) on milk yield of BS cows was significant. HS-related ALMYS provides a robust conceptual framework for diverse sets of productive and animal health data in BS cows, similar to observations in high-yielding HF cattle. However, the limitations associated with the lack of additional data (e.g. immunological indicators) suggest the need for further research to confirm ALMYS in BS breed.

Effects of dietary inclusion of 3 Nordic brown macroalgae on enteric methane emission and productivity of dairy cows

Macroalgae are receiving increased attention as antimethanogenic feed additives for cattle, but most in vivo studies are limited to investigating effects of the red macroalgae Asparagopsis spp. Hence, this study aimed to investigate the CH4 mitigating potential of 3 brown macroalgae from the Northern Hemisphere when fed to dairy cows, and to study the effects on feed intake, milk production, feed digestibility, and animal health indicators. The experiment was conducted as a 4 × 4 Latin square design using 4 lactating rumen, duodenal, and ileal cannulated Danish Holstein dairy cows. The cows were fed a total mixed ration (TMR) without any macroalgae or the same TMR diluted with, on a dry matter basis, either 4% ensiled Saccharina latissima, 4% Ascophyllum nodosum (NOD), or 2% Sargassum muticum (MUT). Each period consisted of 14 d of adaptation, 3 d of digesta and blood sampling, and 4 d of gas exchange measurements using respiration chambers. Milk yield and dry matter intake (DMI) were recorded daily. Blood was sampled on d 13 and 16 and analyzed for health status indicators. None of the 3 species affected the CH4 emission. Moreover, milk yield and DMI were also unaffected. Total-tract digestibility of crude protein was significantly lower for NOD compared with other diets, and additionally, the NOD diet also tended to reduce total-tract digestibility of neutral detergent fiber compared with MUT. Blood biomarkers did not indicate negative effects of the dietary inclusion of macroalgae on cow health. In conclusion, none of the 3 brown macroalgae reduced CH4 emission and did not affect DMI and milk production of dairy cows, whereas negative effects on the digestibility of nutrients were observed when A. nodosum was added. None of the diets would be allowed to be fed in commercial dairy herds due to high contents of iodine, cadmium, and arsenic.

Developmental programming of production and reproduction in dairy cows: I. Association of maternal parity with offspring's birth weight, milk yield, reproductive performance and AMH concentration during the first lactation period

Multiparous dams have been reported to produce offspring with greater fertility and higher AMH concentration, as a marker of ovarian reserves, as compared with nulliparous and primiparous dams. Yet it has remained to be addressed whether this phenomenon can still be true for old multiparous cows which might experience some geriatric changes in their reproductive system. Therefore, the present study was conducted to evaluate the productive and reproductive performance of offspring with different maternal parity. To this end, offspring were classified based on their maternal parities into four categories, including offspring of nulliparous (no previous parity), primiparous (one previous parity), young multiparous (two to six previous parities) and old multiparous (seven or more previous parities) dams. In study I, data of birth weight, milk yield and reproductive variables of 11,788 offspring and data of their maternal parity were retrieved. In study II, blood samples (n = 521) were collected from offspring with various maternal parity for measurement of serum AMH. Birth weight was the lowest in the offspring of nulliparous dams (P < 0.0001) and it was lower in offspring of primiparous and old multiparous dams than offspring of young multiparous dams (P < 0.05). Milk production was the lowest in offspring of old multiparous dams (P < 0.01), and it was lower in offspring of young multiparous dams than offspring of nulliparous and primiparous dams (P < 0.0001). Offspring of old multiparous dams had greater first service conception rate, less services per conception and shorter calving to conception interval than offspring of nulliparous, primiparous and young multiparous dams (P < 0.05). Furthermore, AMH concentration was higher in offspring of old multiparous dams than offspring of nulliparous and primiparous dams (P < 0.05). In conclusion, the present study revealed greater milk production in offspring resulting from dams with lower parity, probably due to the genetic selection for improvement of milk production in dairy cows which imparts the younger generations greater genetic merits for milk production. Reproductive performance, however, was greater in offspring born to dams with higher parity, particularly those born to old multiparous dams, and this phenomenon might be related to their lower milk production and higher AMH concentration.

Effect of heat stress on dairy cow production, reproduction, health, and potential mitigation strategies

Extreme weather events are becoming more common and more severe as a result of climate change, and this has serious implications for the future of livestock, farmer income and livelihoods, and food security worldwide. Dairy cattle have become more heat sensitive due to selective breeding for higher production and increased feedlot operations. The harmful effects of heat stress cause hyperthermia, oxidative stress, and other physiological changes in dairy cows. Environmental heat stress causes a decrease in feed intake, leading to a decrease in milk production in dairy cows. The main method to check for reductions in milk production in dairy cows during the summer is an accurate evaluation of heat stress and effective mitigation strategies. Three primary management strategies have been proposed to reduce heat stress and stabilize dairy cattle performance in increasingly hot and humid climates. Short-term management options include physical alteration of the environment and nutritional management, while long-term management strategy includes discovering heat-tolerant genetic traits and genomic selection for heat tolerance. This review looks at how heat stress has affected the dairy industry’s sustainability and elaborates on genomic selection for thermotolerance in dairy cattle as sustainable breeding practices to increase dairy cows’ ability to withstand high temperatures.

Effect of a garlic and citrus extract supplement on performance, rumen fermentation, methane production, and rumen microbiome of dairy cows

The aim of this trial was to determine the effect of a garlic and citrus extract supplement (GCE) on the performance, rumen fermentation, methane emissions, and rumen microbiome of dairy cows. Fourteen multiparous Nordic Red cows in mid-lactation from the research herd of Luke (Jokioinen, Finland) were allocated to 7 blocks in a complete randomized block design based on body weight, days in milk, dry matter intake (DMI), and milk yield. Animals within each block were randomly allocated to a diet with or without GCE. The experimental period for each block of cows (one for each of the control and GCE groups) consisted of 14 d of adaptation followed by 4 d of methane measurements inside the open circuit respiration chambers, with the first day being considered as acclimatization. Data were analyzed using the GLM procedure of SAS (SAS Institute Inc.). Methane production (g/d) and methane intensity (g/kg of energy-corrected milk) were lower by 10.3 and 11.7%, respectively, and methane yield (g/kg of DMI) tended to be lower by 9.7% in cows fed GCE compared with the control. Dry matter intake, milk production, and milk composition were similar between treatments. Rumen pH and total volatile fatty acid concentrations in rumen fluid were similar, whereas GCE tended to increase molar propionate concentration and decrease the molar ratio of acetate to propionate. Supplementation with GCE resulted in greater abundance of Succinivibrionaceae, which was associated with reduced methane. The relative abundance of the strict anaerobic Methanobrevibacter genus was reduced by GCE. The change in microbial community and rumen propionate proportion may explain the decrease in enteric methane emissions. In conclusion, feeding GCE to dairy cows for 18 d modified rumen fermentation and microbiota, leading to reduced methane production and intensity without compromising DMI or milk production in dairy cows. This could be an effective strategy for enteric methane mitigation of dairy cows.